Abstract
Introduction: In order to obtain the optimal section for super-large cross-section loess tunnels with different overburdens, the ANSYS software is applied in this paper. Methods: Based on the calculation nonconvergence criteria and Mohr-Coulomb criteria, the static stability of loess tunnel section is analyzed by the finite element static strength reduction method. According to the safety factors of rock mass surrounding tunnel in the case of critical failure, the safety factors of super-large cross-section loess tunnel is discussed with different section forms (rectangular cross-section, circular cross-section, horseshoe cross-section and curve wall cross-section) and different overburdens under gravity. Results and Conclusion: The results show that the safety factors of circular section and curve wall cross-section are bigger than the safety factors of the horseshoe cross-section and rectangular cross-section. The curve wall cross-section is considered to be the optimal section because of the fact that the force around the vault and the arch bottom is uniform and symmetrical, and the maximum vertical displacement of the lining is small. The horseshoe cross-section should be avoided in the loess tunnel, because the safety factor of horseshoe cross-section is so small, and stress concentration phenomenon is obvious in the case of deep buried tunnel.
Highlights
In order to obtain the optimal section for super-large cross-section loess tunnels with different overburdens, the ANSYS software is applied in this paper
Lu et al [5] studied the optimal shape of the support section for deep buried tunnel, and obtained the optimal shape of the support section suggesting that the minimum value of the objective function based on the mixed compensation function method could satisfy a given constraint condition by using the conformal mapping method of plane elastic complex variable function to optimize the support section
In the case of super shallow buried tunnel, the range of cross-section strain and stress for super-large crosssection loess tunnel increases with the increase of the safety factor and the maximum critical strain occured at the bottom of arch
Summary
In order to obtain the optimal section for super-large cross-section loess tunnels with different overburdens, the ANSYS software is applied in this paper. Cheng et al [14] analyzed static and dynamic stability of long-span egg shaped loess tunnel without lining by strength reduction method, and obtained the influence on loess tunnel span, the thickness of covering soil and seismic intensity on safety factor and stability. Dong et al [16] analyzed and calculated different cross-sections of tunnel excavated by using ANSYS. All things considered, they believe egg shaped section is the most reasonable form
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
